"DANorgard" wrote in message ...
Unfortunately I've done it several times. If its stuck to the rock you can
tape a stiff toothbrush at the opening of the tube. I bought one of those
hollow- handled dish scrubbers that you fill with soap and have bristles on
them. Drill a hole in the handle and insert the tube then drill a 1/2" hole
in the bristle base to let the water flow in.

Interesting - I tried this with Derbesia and Bryopsis and it did not work.
I must have done it some wrong way... I noticed the algae holds to the rocks
to strongly to be sucked off. I was rather using wooden spatula split at
the end and I tried to wrap algae strands around the wooden stick - I was
making something like cotton swabs with algae hair...
Of course some of it was always left on the rocks so if you do not improve
water quality removing algae this way would be your weekly entertainment ;-)